Increasing pH causes faster anion-and cation-transport rates through a synthetic ion channel.

Ion-channel mimics are able to transmit electrical signals across phospholipid membranes, and can be envisioned as nanoswitches for molecular electronics. Here, we reported the use of pH to alter ion-transport rates through a synthetic aminocyclodextrin ion channel. Both cation- and anion-transport rates were found to increase with an increase in pH due to the unique electrostatics of the multiple ammonium groups that line the channel pore. Such pH regulation of ion transport rates is unique and can be exploited for sensing applications.